1. Field of the Invention
The present invention relates to a circuit arrangement for permitting the addressing of a disc storage device of a first type with addresses which directly address storage zones of a disc storage device of a second type.
2. The Prior Art
Disc storage devices are used in systems which process data signals, such as a teleprinter and data exchange system. In such a system, the disc storage devices serve reliably to store programmed data and information data relative to individual subscriber stations which are connected to the system. The disc storage device is subdivided into a plurality of storage cylinders, each of which has at least one storage track at each disc level.
In the type of data exchange system known as an EDS, circuit arrangement of the type referred to above is employed, using disc storage devices. In the past, only one type of magnetic disc storage device has been used in such a system. (See "Unterrichsblatter der Deutschen Bundespost" (B) edition 26/1973, No. 12, pages 307 to 314.) When such a system must be extended in storage capacity, it sometimes happens that the type of disc storage device used in the exchange system is no longer available, and must be replaced by a different type of disc storage device. Normally this requires different operating programs in order to read and write data from the programs used with the original disc storage devices. This is because the different types of disc storage devices are frequently of different size, contain different storage formats, and are operated by different forms of addressing. Thus, a relatively high development effort is required in order to use different types of disc storage devices in a single system, or to replace one type of disc storage device with another type.